The use of sensitive chemical antibodies for diagnosis: detection of low levels of Epcam in breast cancer

EpCAM is expressed at low levels in a variety of normal human epithelial tissues, but is overexpressed in 70–90% of carcinomas. From a clinico-pathological point of view, this has both prognostic and therapeutic significance. EpCAM was first suggested as a therapeutic target for the treatment of epithelial cancers in the 1990s. However, following several immunotherapy trials, the results have been mixed. It has been suggested that this is due, at least in part, to an unknown level of EpCAM expression in the tumors being targeted. Thus, selection of patients who would benefit from EpCAM immunotherapy by determining EpCAM status in the tumor biopsies is currently undergoing vigorous evaluation. However, current EpCAM antibodies are not robust enough to be able to detect EpCAM expression in all pathological tissues.

Here we report a newly developed EpCAM RNA aptamer, also known as a chemical antibody, which is not only specific but also more sensitive than current antibodies for the detection of EpCAM in formalin-fixed paraffin-embedded primary breast cancers. This new aptamer, together with our previously described aptamer, showed no non- specific staining or cross-reactivity with tissues that do not express EpCAM. They were able to reliably detect target proteins in breast cancer xenograft where an anti-EpCAM antibody (323/A3) showed limited or no reactivity. Our results demonstrated a more robust detection of EpCAM using RNA aptamers over antibodies in clinical samples with chromogenic staining. This shows the potential of aptamers in the future of histopathological diagnosis and as a tool to guide targeted immunotherapy.

Effects of message framing on breast-cancer-related beliefs and behaviours: the role of mediating factors

The effects of gain-loss message framing on breast-cancer-related cognitions and behaviors were assessed among 539 women aged 30 to 70 years. The design involved a prebrochure telephone interview, followed by a brochure mailout, and a postbrochure telephone interview. The brochures contained information about breast cancer and the risk of family history. Recommended behaviors were framed to emphasize gains, losses, or were neutral; and statistical risk information was presented either positively or negatively. Measures included demographics, family history, breast self-examination (BSE) performance, BSE intention, self-efficacy in performing BSE, perceived early detection risk of breast cancer, perceived susceptibility to breast cancer, and anxiety about breast cancer. A loss-framed message led to greater positive change in BSE behavior. Interactions between framing effects and variables of issue involvement, perceived early detection risk, and self-efficacy indicated effects on behavior, but not beliefs.

Correlation between extent of osteolytic damage and metastatic burden of human breast cancer metastasis in nude mice: Real-time PCR quantitation

Orthotopic or intracardiac injection of human breast cancer cell lines into immunocompromised mice allows study of the molecular basis of breast cancer metastasis. We have established a quantitative real-time PCR approach to analyze metastatic spread of human breast cancer cells inoculated into nude mice via these routes. We employed MDA-MB-231 human breast cancer cells genetically tagged with a bacterial β-galactosidase (Lac-Z) retroviral vector, enabling their detection by TaqMan® real-time PCR. PCR detection was linear, specific, more sensitive than conventional PCR, and could be used to directly quantitate metastatic burden in bone and soft organs. Attesting to the sensitivity and specificity of the PCR detection strategy, as few as several hundred metastatic MDA-MB-231 cells were detectable in 100 μm segments of paraffin-embedded lung tissue, and only in samples adjacent to sections that scored positive by histological detection. Moreover, the measured real-time PCR metastatic burden in the bone environment (mouse hind-limbs, n=48) displayed a high correlation to the degree of osteolytic damage observed by high resolution X-ray analysis (r 2=0.972). Such a direct linear relationship to tumor burden and bone damage substantiates the so-called `vicious cycle' hypothesis in which metastatic tumor cells promote the release of factors from the bone which continue to stimulate the tumor cells. The technique provides a useful tool for molecular and cellular analysis of human breast cancer metastasis to bone and soft organs, can easily be extended to other cell/marker/organ systems, and should also find application in preclinical assessment of anti-metastatic modalities.

Effectiveness, costs, and cost-effectiveness of recruitment strategies for a mammographic screening program to detect breast cancer

BACKGROUND AND PURPOSE: Since effective and affordable recruitment methods are essential for the widespread implementation of mammographic screening for detection of breast cancer, we studied the effectiveness, the costs, and the cost-effectiveness of various recruitment strategies in the population targeted by a pilot Australian program that offered free mammography screening between 1988 and 1990. METHODS: We evaluated three public recruitment strategies--local newspaper articles, community promotion, and promotion to physicians--and five personal strategies--invitation letters with or without specified appointment times, either alone or with a follow-up letter, or telephone call to nonattenders. The effectiveness of public recruitment strategies was estimated from monthly attendance rates by Poisson regression analysis, while the probability of attendance in response to personal strategies was calculated using logistic regression analysis. Costs were determined by resource usage studies. The cost-effectiveness ratios for personal strategies were determined using decision analysis. RESULTS: The costs in 1988-1989 Australian dollars per woman recruited were $22 for local newspaper articles and $106 for community promotion. No detectable increase in attendance resulted from promotion to physicians. When the cost of reserving an appointment was considered, the most cost-effective personal recruitment strategy was an invitation letter without a specified appointment time, followed by a second letter to nonattenders. This strategy recruited 35.6% of women in the sample targeted and cost $10.52 per attendee. In comparison, the most effective personal recruitment strategy was a letter with a specified appointment time followed by a second letter to nonattenders, which recruited 44.1% of women at an average cost of $19.99 and a marginal cost of $59.71 per additional attendee. CONCLUSIONS: Personal recruitment strategies were more cost-effective than public strategies. The most cost-effective personal strategy was an invitation letter without a specified appointment time, followed by a second letter to nonattenders.

Women's perceptions of familial aspects of breast cancer

Women’s understanding of familial aspects of breast cancer was examined using both focus groups and interviews. The studies covered issues related to perceptions of breast cancer risk factors, perceived breast cancer risk, understanding of risk information, and family history of breast cancer as a risk factor. Study 1 consisted of four focus group discussions with women from the general community. Study 2 comprised ten face-to-face interviews with women who had a family history of breast cancer. The results in combination indicate a fairly high level of awareness of family history as a risk factor for breast cancer. However, the definition of a familial history of breast cancer differed between the groups, with those without a family history being more inclusive than those with such a history. The paper concludes with suggestions for use by those developing resources materials for those with a familial history of breast cancer.

Experiences of men with breast cancer: a qualitative study

Background
Recent reports indicate that male breast cancer rates are increasing in North America. While there have been numerous large-scale studies examining women's experiences with breast cancer, to date there have been no North American studies examining what a man experiences with a breast cancer diagnosis. The objective of this qualitative study was to describe the experiences of a sample of Canadian men diagnosed with breast cancer.

Methods
After written informed consent, unstructured audio-taped interviews were conducted with 20 men. Since little is known about a man's experience with breast cancer, an exploratory qualitative approach was utilized.

Results
Participants experienced concerns related to the lack of awareness of male breast cancer within both public and health professional groups. Many men suffered stress related to the cancer diagnosis, body image concerns and role strain. The lack of male-specific breast cancer information was identified as a major concern. All denied interest in traditional support groups. In retrospect, a number of men felt the breast cancer experience vastly improved their lives.

Conclusions
Needs identified by participants include increased public and health professional awareness of male breast cancer, written information specific for men, and male participation in breast cancer research. Further study is also necessary to identify supports considered helpful by men with breast cancer and other malignancies.

Kernel-based naive bayes classifier for breast cancer prediction

The classification of breast cancer patients is of great importance in cancer diagnosis. Most classical cancer classification methods are clinical-based and have limited diagnostic ability. The recent advances in machine learning technique has made a great impact in cancer diagnosis. In this research, we develop a new algorithm: Kernel-Based Naive Bayes (KBNB) to classify breast cancer tumor based on memography data. The performance of the proposed algorithm is compared with that of classical navie bayes algorithm and kernel-based decision tree algorithm C4.5. The proposed algorithm is found to outperform in the both cases. We recommend the proposed algorithm could be used as a tool to classify the breast patient for early cancer diagnosis.

Metallothionein 2A expression is associated with cell proliferation in breast cancer

Metallothioneins (MTs) belong to a family of cysteine-rich, metal-binding intracellular proteins, which have been linked with cell proliferation. In this study, expression levels of the 8 known MT-1 and MT-2 functional isoforms in human invasive ductal breast cancer specimens were determined by RT–PCR. The expression profiles of the MT protein and MT-2A mRNA were further evaluated in 79 cases of human invasive ductal breast carcinoma by immunohistochemistry and in situ hybridization, and correlated with cancer cell proliferation (determined by Ki-67 nuclear antigen immunolabeling). MT-1A, MT-1E, MT-1F, MT-1G, MT-1H, MT-1X and MT-2A but not MT-1B, were detected in breast cancer tissue samples. The MT-2A mRNA transcript was the highest among all the isoforms detected. A positive correlation was observed between MT-2A mRNA and MT protein expression with Ki-67 labeling (P = 0.0003 and P < 0.0001, respectively) but not with apoptosis (P = 0.1244 and P = 0.8189, respectively). Co-localization of the MT protein and Ki-67 nuclear antigen in breast cancer cells was demonstrated by double immunofluorescence staining. There was also significantly higher MT protein and MT-2A mRNA expression in histological grade 3 tumors than in histological grade 1 and 2 tumors. The finding that MT 2A appears to be the main isoform associated with cell proliferation in invasive ductal breast cancer tissues, may have therapeutic implications.

External breast prosthesis use: experiences and views of women with breast cancer, breast care nurses, and prosthesis fitters

After mastectomy, the provision of an appropriate breast prosthesis can help to improve body image and quality of life and reduce associated emotional distress. Although up to 90% of women use an external breast prosthesis after mastectomy, little is known about their experiences and satisfaction with breast prosthesis use. Focus groups were conducted with women who had been fitted with an external breast prosthesis, breast care nurses, and prosthesis fitters to explore women's experiences of prosthesis use. Qualitative thematic content analysis of focus group transcripts indicated that whereas women's initial reaction to the prosthesis generally was negative, this improved over time. Provision of adequate information and support, characteristics of the fitter and the fitting experience, and relationships with breast care nurses and prosthesis fitters were important to women's acceptance and satisfaction with their prosthesis. The study results highlighted the key role that breast care nurses play and the underestimation of the prosthesis fitter's role. Common themes concerning the impact of prosthesis use included body image, appearance, and feminine identity. These findings have important implications for professionals involved in the delivery of breast prostheses services.

The breast cancer related burden of morbidity and mortality in six European coutries

Background: The burden of breast cancer expressed in Disability Adjusted Life Years (DALYs) was compared for six European countries and its sensitivity to different sources of variation examined. Methods: DALYs were calculated using country-specific epidemiological data and European Disability Weights. Epidemiological data for 1996 were obtained for Denmark, England and Wales, France, the Netherlands, Spain and Sweden. Disability weights were empirically derived. Results:  Denmark and the Netherlands lost the largest number of DALYs (approximately 1100 DALYs per 100,000 women). They were followed by England (87% of the Danish burden), France (72%), Sweden (68%) and Spain (67%). 70 to 80% of the burden was caused by mortality. Cross-national variation in disease epidemiology was the largest source of variation in the burden of breast cancer. Variation in disability weights and uncertainty in epidemiological data had smaller effects. Conclusion: To compare the burden of breast cancer and most other types of cancer mortality rates provide sufficient information.

Ets2 maintains hTERT gene expression and breast cancer cell proliferation by interacting with c-Myc

Human telomerase reverse transcriptase (hTERT) underlies cancer cell immortalization, and the expression of hTERT is regulated strictly at the gene transcription. Here, we report that transcription factor Ets2 is required for hTERT gene expression and breast cancer cell proliferation. Silencing Ets2 induces a decrease of hTERT gene expression and increase in human breast cancer cell death. Reconstitution with recombinant hTERT rescues the apoptosis induced by Ets2 depression. In vitro and in vivo analyses show that Ets2 binds to the EtsA and EtsB DNA motifs on the hTERT gene promoter. Mutation of either Ets2 binding site reduces the hTERT promoter transcriptional activity. Moreover, Ets2 forms a complex with c-Myc as demonstrated by co-immunoprecipitation and glutathione S-transferase pulldown assays. Immunological depletion of Ets2, or mutation of the EtsA DNA motif, disables c-Myc binding to the E-box, whereas removal of c-Myc or mutation of the E-box also compromises Ets2 binding to EtsA. Thus, hTERT gene expression is maintained by a mechanism involving Ets2 interactions with the c-Myc transcription factor and the hTERT gene promoter, a protein-DNA complex critical for hTERT gene expression and breast cancer cell proliferation.